jackson-databind has case-insensitive deserialization bypasses per-property @JsonIgnoreProperties

Description

## Summary In `BeanDeserializerBase.createContextual()`, per-property `@JsonIgnoreProperties` exclusions are applied by `_handleByNameInclusion()`, producing a `contextual` deserializer whose `BeanPropertyMap` has the ignored properties removed. The subsequent per-property case-insensitivity block (triggered by `@JsonFormat(ACCEPT_CASE_INSENSITIVE_PROPERTIES)`) rebuilds from `this._beanProperties` (the original, unfiltered map) instead of `contextual._beanProperties`, then overwrites the filtered map — restoring every property `_handleByNameInclusion` had just removed. The ignored property becomes writable again. ## Impact An application that both enables case-insensitive matching and relies on per-property `@JsonIgnoreProperties` to keep a field unwritable can have that field set from untrusted JSON (mass-assignment-style write). ## Affected / Patched Fixed in 2.18.9, 2.21.5 and 3.1.4. ## Severity / CWE Maintainer: minor. Reporter: Moderate. CWE-915. ## Upstream fix FasterXML/jackson-databind#5962 (PR #5964, `0e1b0b2`), milestone 3.1.4. Released 2026-06-04. ## Credits Omkhar Arasaratnam (@omkhar) - finder.

Affected Packages (2)